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2B-FLXHR-LIDAR

This algorithm derives estimates of broadband fluxes and heating rates consistent with liquid and ice water content estimates from the CloudSat Profiling Radar (CPR), CALIPSO, and MODIS. For each radar profile, a broadband radiative transfer model is used to calculate upwelling and downwelling longwave and shortwave fluxes at each CPR range gate from the surface to the lower stratosphere. Profiles of cloud ice and liquid water content and cloud particle effective radii are defined based on the CloudSat 2B-LWC and 2B-IWC products while precipitation properties are defined using the CloudSat 2C-PRECIP-COLUMN dataset. The properties of thin or low clouds that are not detected by CloudSat are assigned based on CALIOP backscatter, CALIPSO’s CAL_LID_L2_05kmCLay, and the CloudSat 2B-TAU product while aerosol location and optical properties are specified using CALIPSO’s CAL_LID_L2_05kmALay product. Ancillary atmospheric state variables are interpolated from ECMWF analyses and surface albedos are assigned based on seasonally-varying maps of surface reflectance properties in combination with daily snow and sea ice cover maps from passive microwave instruments. Two additional sets of flux calculations are performed with all clouds and all aerosols removed, respectively. Corresponding profiles of atmospheric heating are inferred from the vertical derivative of these fluxes.

Control Frame 0, CPR Calibration
16: CPR to point in 160 seconds
17: CPR 15º to the right
18: CPR 15º to the left
19: CPR 10º to the right -- default rotation
20: CPR 10º to the left -- default rotation
21: CPR 5º to the right
22: CPR 5º to the left
23 - 29: Target ID for testing - not planned for operational use
30 - 36: CPR rotation - not planned for operational use
37 - 39: Not planned for operational use

Control Frame 1, Four thruster closed-loop
40: Rotation into the OR orientation
41: Rotation into the x-track along the anti-ang momentum
42: Rotation into the x-track along ang momentum
43: Rotation into the orbit lower orientation
44: Rotation into alt. OR w/ CPR away from Sun
45 - 49: Not planned for operational use

Control Frame 2, One thruster open-loop
50: Rotation into the OR orientation
51: Rotation into the x-track along the anti-ang momentum
52: Rotation into the x-track along ang momentum
53: Rotation into the orbit lower orientation
54: Rotation into alt. OR w/ CPR away from Sun
55 - 59: Not planned for operational use

Control Frame 3, Two thruster open-loop
60: Rotation into the OR orientation
61: Rotation into the x-track along the anti-ang momentum
62: Rotation into the x-track along ang momentum
63: Rotation into the orbit lower orientation
64: Rotation into alt. OR w/ CPR away from Sun
65 - 69: Not planned for operational use

Control Frame 4, Four thruster open-loop
70: Rotation into the OR orientation
71: Rotation into the x-track along the anti-ang momentum
72: Rotation into the x-track along ang momentum
73: Rotation into the orbit lower orientation
74: Rotation into alt. OR w/ CPR away from Sun
75 - 80: Not planned for operational use

Control Frame 5
81: Body into the x-track along the anti-ang momentum
82 - 1023: Not planned for operational use

Determines whether or not lidar data was used for each ray. Values of 1 and 2 correspond to cases where extra cloud is defined based on GEOPROF-lidar in day and night scenes, respectively. Values of 3 and 4 indicate no additional clouds were found.

The scene status flag is a 16-bit flag with values indicating whether or not the external products are used in any given pixel. The flag will indicate whether the pixel was observed during the day or at night, cloud and aerosol detected by CALIPSO are flagged,
along with information on the use of AMSR-E and precipitation from 2C-PRECIP-COLUMN. For 2B-FLXHR there
are components of the status flag that will always be turned on, such as: Missing 2B-Tau, missing CALIOP.

The pitch angle offset from nadir during normal operations. Pitch up is positive (radar points along the flight track in the direction of motion), down is negative (radar points along the flight track opposite the direction of motion).

Related News Articles

2016

CloudSat releases algorithm uncertainty study

September 1, 2016

The CloudSat algorithm development leads have completed a synthesis of algorithm uncertainties. The synopsis describes the known uncertainties in the Cloudsat algorithms and provides the relevant technical and peer reviewed references for data end-users. The algorithm development team plans to update the document periodically as new data releases become available.